Heads up - Promotion on 30/01/17 - 19/02/17.
I have been using Redex (both petrol & diesel) for a few years now. The old Toyota Corolla Verso showed a better mileage per tank by about 10-15% (from 300 miles to 330 to 350), car is also much smoother. Now using diesel for my new car.
I'll be picking up a few boxes from Costco next week. Hope this helps anyone who uses this.
** These are typically selling between £22 - £25, so almost 50% off. **
thx mudd: Updated as suggested